space exploration news & perspectives

During the preparation and transmission of any interstellar radio messages (IRMs), some scientific and technological issues need to be addressed. The paper «Messaging to Extra-Terrestrial Intelligence» (METI) [1] lists nine of such issues. We propose to rank planned and already sent IRMs depending on how well three basic METI’s issues are resolved in them. These basic issues are the following: (1) choice of the target stars, (2) energy required per bit of the information, and (3) availability of a special digital or analog key to allow Aliens to decode our message, [2]. In order to rank IRMs, it is necessary to find out whether there are serious concerns regarding of how these three issues were addressed.